1. Field of the Invention
The present invention relates to an image measuring apparatus and an image measuring method.
2. Description of Related Art
Conventionally, there is known an image measuring apparatus which captures an image of a measurement location of a work piece by a CCD (Charge Coupled Device) camera or the like and performs edge detection, pattern matching and the like in the captured image (for example, see JP H8-247719).
Edge detection is a technique to determine whether the work piece is the desired work piece or not and the like by obtaining edge information (position coordinate and the like) of a measurement target graphic included in a captured image based on edge detection tools T set by an operator as shown in FIG. 11 and by measuring the position, width, height and the like of the measurement target graphic as shown in FIG. 12, for example.
Moreover, pattern matching is a technique to determine whether the work piece is the desired work piece or not and the like by measuring position aberration, angle aberration and the like, for example, of the work piece by comparing the measurement target graphic included in the captured image to a template image which is registered in advance.
However, the conventional image measuring apparatus is troublesome because the edge detection tool T needs to be set to a plurality of locations manually by an operator to carry out edge detection.
Further, the conventional image measuring apparatus is troublesome to carry out pattern matching because a template image needs to be registered according to the shape of the measurement target graphic. Furthermore, when the direction, size and the like of the measurement target graphic are different from those of the template image, there are inconveniences such that the processing needs more time and that the pattern matching cannot be performed.